X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=compiler%2Frustc_expand%2Fsrc%2Fproc_macro_server.rs;h=7bf6502c976ca6d69fd49aa978ee6df9f0ae0406;hb=bc26def1d5d21527e70a1d161ed69bd00fb7fb4c;hp=1ea26b4eab44b3069ee73c8fcf0810a5016fe545;hpb=50489e3b0048af4df6f0a92bb43af8afce9b6652;p=rust.git

diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs
index 1ea26b4eab4..7bf6502c976 100644
--- a/compiler/rustc_expand/src/proc_macro_server.rs
+++ b/compiler/rustc_expand/src/proc_macro_server.rs
@@ -1,4 +1,4 @@
-use crate::base::ExtCtxt;
+use crate::base::{ExtCtxt, ResolverExpand};
 
 use rustc_ast as ast;
 use rustc_ast::token;
@@ -7,6 +7,7 @@
 use rustc_ast::tokenstream::{self, CanSynthesizeMissingTokens};
 use rustc_ast::tokenstream::{DelimSpan, Spacing::*, TokenStream, TreeAndSpacing};
 use rustc_ast_pretty::pprust;
+use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::Diagnostic;
 use rustc_lint_defs::builtin::PROC_MACRO_BACK_COMPAT;
@@ -14,6 +15,8 @@
 use rustc_parse::lexer::nfc_normalize;
 use rustc_parse::{nt_to_tokenstream, parse_stream_from_source_str};
 use rustc_session::parse::ParseSess;
+use rustc_span::def_id::CrateNum;
+use rustc_span::hygiene::ExpnId;
 use rustc_span::hygiene::ExpnKind;
 use rustc_span::symbol::{self, kw, sym, Symbol};
 use rustc_span::{BytePos, FileName, MultiSpan, Pos, RealFileName, SourceFile, Span};
@@ -355,22 +358,34 @@ pub struct Literal {
 }
 
 pub(crate) struct Rustc<'a> {
+    resolver: &'a dyn ResolverExpand,
     sess: &'a ParseSess,
     def_site: Span,
     call_site: Span,
     mixed_site: Span,
     span_debug: bool,
+    krate: CrateNum,
+    expn_id: ExpnId,
+    rebased_spans: FxHashMap<usize, Span>,
 }
 
 impl<'a> Rustc<'a> {
-    pub fn new(cx: &'a ExtCtxt<'_>) -> Self {
+    pub fn new(cx: &'a ExtCtxt<'_>, krate: CrateNum) -> Self {
         let expn_data = cx.current_expansion.id.expn_data();
+        let def_site = cx.with_def_site_ctxt(expn_data.def_site);
+        let call_site = cx.with_call_site_ctxt(expn_data.call_site);
+        let mixed_site = cx.with_mixed_site_ctxt(expn_data.call_site);
+        let sess = cx.parse_sess();
         Rustc {
-            sess: &cx.sess.parse_sess,
-            def_site: cx.with_def_site_ctxt(expn_data.def_site),
-            call_site: cx.with_call_site_ctxt(expn_data.call_site),
-            mixed_site: cx.with_mixed_site_ctxt(expn_data.call_site),
+            resolver: cx.resolver,
+            sess,
+            def_site,
+            call_site,
+            mixed_site,
             span_debug: cx.ecfg.span_debug,
+            krate,
+            expn_id: cx.current_expansion.id,
+            rebased_spans: FxHashMap::default(),
         }
     }
 
@@ -623,10 +638,11 @@ fn path(&mut self, file: &Self::SourceFile) -> String {
         match file.name {
             FileName::Real(ref name) => name
                 .local_path()
+                .expect("attempting to get a file path in an imported file in `proc_macro::SourceFile::path`")
                 .to_str()
                 .expect("non-UTF8 file path in `proc_macro::SourceFile::path`")
                 .to_string(),
-            _ => file.name.to_string(),
+            _ => file.name.prefer_local().to_string(),
         }
     }
     fn is_real(&mut self, file: &Self::SourceFile) -> bool {
@@ -713,6 +729,51 @@ fn resolved_at(&mut self, span: Self::Span, at: Self::Span) -> Self::Span {
     fn source_text(&mut self, span: Self::Span) -> Option<String> {
         self.sess.source_map().span_to_snippet(span).ok()
     }
+    /// Saves the provided span into the metadata of
+    /// *the crate we are currently compiling*, which must
+    /// be a proc-macro crate. This id can be passed to
+    /// `recover_proc_macro_span` when our current crate
+    /// is *run* as a proc-macro.
+    ///
+    /// Let's suppose that we have two crates - `my_client`
+    /// and `my_proc_macro`. The `my_proc_macro` crate
+    /// contains a procedural macro `my_macro`, which
+    /// is implemented as: `quote! { "hello" }`
+    ///
+    /// When we *compile* `my_proc_macro`, we will execute
+    /// the `quote` proc-macro. This will save the span of
+    /// "hello" into the metadata of `my_proc_macro`. As a result,
+    /// the body of `my_proc_macro` (after expansion) will end
+    /// up containg a call that looks like this:
+    /// `proc_macro::Ident::new("hello", proc_macro::Span::recover_proc_macro_span(0))`
+    ///
+    /// where `0` is the id returned by this function.
+    /// When `my_proc_macro` *executes* (during the compilation of `my_client`),
+    /// the call to `recover_proc_macro_span` will load the corresponding
+    /// span from the metadata of `my_proc_macro` (which we have access to,
+    /// since we've loaded `my_proc_macro` from disk in order to execute it).
+    /// In this way, we have obtained a span pointing into `my_proc_macro`
+    fn save_span(&mut self, mut span: Self::Span) -> usize {
+        // Throw away the `SyntaxContext`, since we currently
+        // skip serializing `SyntaxContext`s for proc-macro crates
+        span = span.with_ctxt(rustc_span::SyntaxContext::root());
+        self.sess.save_proc_macro_span(span)
+    }
+    fn recover_proc_macro_span(&mut self, id: usize) -> Self::Span {
+        let resolver = self.resolver;
+        let krate = self.krate;
+        let expn_id = self.expn_id;
+        *self.rebased_spans.entry(id).or_insert_with(|| {
+            let raw_span = resolver.get_proc_macro_quoted_span(krate, id);
+            // Ignore the deserialized `SyntaxContext` entirely.
+            // FIXME: Preserve the macro backtrace from the serialized span
+            // For example, if a proc-macro crate has code like
+            // `macro_one!() -> macro_two!() -> quote!()`, we might
+            // want to 'concatenate' this backtrace with the backtrace from
+            // our current call site.
+            raw_span.with_def_site_ctxt(expn_id)
+        })
+    }
 }
 
 // See issue #74616 for details
@@ -722,10 +783,10 @@ fn ident_name_compatibility_hack(
     rustc: &mut Rustc<'_>,
 ) -> Option<(rustc_span::symbol::Ident, bool)> {
     if let NtIdent(ident, is_raw) = nt {
-        if let ExpnKind::Macro(_, macro_name) = orig_span.ctxt().outer_expn_data().kind {
+        if let ExpnKind::Macro { name: macro_name, .. } = orig_span.ctxt().outer_expn_data().kind {
             let source_map = rustc.sess.source_map();
             let filename = source_map.span_to_filename(orig_span);
-            if let FileName::Real(RealFileName::Named(path)) = filename {
+            if let FileName::Real(RealFileName::LocalPath(path)) = filename {
                 let matches_prefix = |prefix, filename| {
                     // Check for a path that ends with 'prefix*/src/<filename>'
                     let mut iter = path.components().rev();
@@ -788,7 +849,7 @@ fn ident_name_compatibility_hack(
                 if macro_name == sym::tuple_from_req && matches_prefix("actix-web", "extract.rs") {
                     let snippet = source_map.span_to_snippet(orig_span);
                     if snippet.as_deref() == Ok("$T") {
-                        if let FileName::Real(RealFileName::Named(macro_path)) =
+                        if let FileName::Real(RealFileName::LocalPath(macro_path)) =
                             source_map.span_to_filename(rustc.def_site)
                         {
                             if macro_path.to_string_lossy().contains("pin-project-internal-0.") {